1. Field of the Invention
The invention is related to a semiconductor structure and a manufacturing method thereof, and more particularly, to a light emitting diode structure and a manufacturing method thereof.
2. Description of Related Art
In general, in the manufacturing method of the light emitting diode structure, an epitaxy layer is first grown on an epitaxy substrate. However, since the epitaxy substrate absorbs light, a wafer bonding method is needed to bond the epitaxy layer and a transparent transfer-substrate. Next, the epitaxy substrate is removed so the epitaxy layer may be transferred onto the transfer-substrate to avoid affecting light emission. Currently, the material of the adhesive layer used by the wafer bonding method includes silicon dioxide or benzocyclobutene (BCB). When a silicon dioxide layer is used as the adhesive layer, silicon dioxide needs to first be deposited on the transfer-substrate via plasma enhanced chemical vapor deposition (PECVD). Then, a polishing process and an activation process are performed on the deposited silicon dioxide layer to form a good bonding surface. Next, the epitaxy layer and the transfer-substrate are aligned, and the epitaxy layer and the transfer-substrate are bonded via a method of a high temperature (such as 300° C.) for a long time (such as 1 hour) and a high pressure (such as 3,000 N/cm2). Lastly, the epitaxy substrate is removed to complete the manufacture of the light emitting diode.
When a benzocyclobutene layer is used as the adhesive layer, benzocyclobutene needs to first be coated on the epitaxy layer and the transfer-substrate via a spin coating method. Then, a baking procedure is performed on the coated benzocyclobutene. Next, the epitaxy layer and the transfer-substrate are aligned, and the epitaxy layer and the transfer-substrate are bonded via a method of a high temperature (such as 220° C.) for a long time (such as 3 hours) and a low pressure (such as 1,100 N/cm2). Lastly, the epitaxy substrate is removed to complete the manufacture of the light emitting diode. However, the costs required for the two manufacturing methods are higher and the manufacturing steps are more complex. Moreover, since both materials require a high temperature for a long time to bond the epitaxy layer and the transfer-substrate, defects may be generated in the epitaxy layer and the quality thereof may be damaged due to the high temperature. Therefore, the luminous efficiency of the resulting light emitting diode structure may be affected.